I voted for "Production".
There are plenty of books on taste - Pip Hills' "Appreciating Whisky" probably being the most indepth, and of course, MJ and JM have given us tasting notes for just about every whisky.
History? Well, there's a number of books on that front as well.
But how often have we all contributed to these pages saying something like, "I wonder what sort of malt they used?" or "Where did they get their casks from?" or "Would the Lomond stills have contributed to the flavour any differently", etc, etc.
We all know the production process - barley -> malt -> wort -> wash -> new make -> whisky, etc, etc, but what about the nitty gritty of what a distillery ACTUALLY does. What goes on behind the scenes? What decision or action does this distillery do that makes it different to others? That's what I'm interested in!